package com.example.letswalk.util;
import java.security.Security;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.InvalidParameterSpecException;
public class AesCbcUtil {
    static {
        //BouncyCastle是一个开源的加解密解决方案，主页在http://www.bouncycastle.org/        
        Security.addProvider(new BouncyCastleProvider());
    }
    public static String decrypt(String data, String key, String iv) throws Exception {
        //        initialize();         //被加密的数据        
        byte[] dataByte = Base64.decodeBase64(data);
        //加密秘钥        
        byte[] keyByte = Base64.decodeBase64(key);
        //偏移量        
        byte[] ivByte = Base64.decodeBase64(iv);
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);
            // 初始化            
            byte[] resultByte = cipher.doFinal(dataByte);
            if(null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                return result;
        }
return null;
} catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
} catch (NoSuchPaddingException e) {
            e.printStackTrace();
} catch (InvalidParameterSpecException e) {
            e.printStackTrace();
} catch (InvalidKeyException e) {
            e.printStackTrace();
} catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
} catch (IllegalBlockSizeException e) {
            e.printStackTrace();
} catch (BadPaddingException e) {
            e.printStackTrace();
} catch (UnsupportedEncodingException e) {
            e.printStackTrace();
}
return null;
}
}